How do you catch Kyogre and Groudon without a Master Ball?

Answer 1

This is what I would do. I would have a fairly strong Pokemon, around 5 levels above the legendary, who knows a move that is super effective against the legendary and can have a status effect. For example, Ice Beam/Blizzard (although I do not use Blizzard because it is too strong) can freeze Groundon, and Shock Wave/Thunder Bolt/Thunder can paralyze Kyogre. After they have the status on them, I switch out to a low level Pokemon (Level 29, 30) to use weak moves like Cut, Rock Smash, Tackle, to get their HP down 1 point by 1 point. Then, I use Ultra Balls, Pokeballs, and Great Balls, etc. Get a Swellow or a Pokemon that can learn Endeavor and train it until it does. When it does learn Endeavor, DO NOT TRAIN IT ANY FURTHER. Find a Focus Band or Focus Sash and give it to the Pokemon. When you battle the legendary, if the legendary uses an attack that inflicts damage (and the legendary is sure to hit first) hits, the Pokemon should hang on using its Focus Band/Focus Sash. Use Endeavor, and the legendary will be at 1 HP! Then switch out to a Pokemon that has a status attack such as Thunder Wave, Sleep Powder, etc. to inflict the status on the legendary. Then use Ultra Balls, Great Balls, Pokeballs, etc.